1. Field of the Invention
The present invention is directed to the field of drug delivery devices, and more particularly is directed to a process for electroplating a porous layer for holding and delivering a drug.
2. Description of Related Art
Drug delivered directly to adjacent tissue can provide a pharmacological action superior to response generated by the drug if taken orally, intravenously or by other means. The direct application of a drug to the tissue or organ requiring treatment can avoid toxic effects of the drug on healthy tissue and organs and avoids the body's natural ability to remove drug or destroy it before the drug can reach the intended target. Direct drug delivery can be achieved through a variety of devices, including through transdermal, subcutaneous and implanted devices. Recently, efforts have been made to develop stents that are capable of drug delivery.
It is also often desirable to deliver the drug over an extended time. Timed released drugs result in a more uniform drug concentration over time and the benefits are well known and understood by the medical profession. Many systems for timed released drugs and direct drug delivery to adjacent tissue employ a polymer or other non-drug material to control the release of the drug. The drug release rate is slowed by diffusion through the polymer, or the drug can be released as the polymer degrades or disintegrates in the body. However, the polymer used to control the release of the drug can complicate the drug delivery process. For example, reactions between the polymer and the drug may change the drug before it reaches the target tissue, or the polymer or its disintegration products may produce undesirable cellular responses. In addition, it is often difficult to adhere the polymer to the delivery device. Thus, a need remains for a drug delivery device that can be used to directly deliver a drug over a sustained period of time.